1. Field of the Invention
The invention concerns a hand-held apparatus for the examination of biological liquids such as whole blood, liquor, urine and serum by electrochemical biosensors without conducting costly preceding analysis.
2. Discussion of the Prior Art
For a fairly long time biosensors have been used as sensitive and selective detection methods in analyses, and in particular in medical diagnostics. For this purpose, respective biosensors are installed in analysers which permit a fast, inexpensive and notably proper examination of the respective parameters in central laboratories where many samples have to be examined. This requires, as a rule, a sample throughput of 80–180/h.
The analysers are based on various principles. For the most part, they are operated with a continuous air segmented flow of the respective, highly diluted laboratory samples, i.e. This method requires the preparation of the solutions to be examined (e.g. whole blood) with a dilution of the analysis material being required. It is very costly to analyse individual samples using this equipment as the efficiency of analysers becomes effective only in the case of a great number of Prüfgeräte-Werk Medingen GmbH, EBIO (Eppendorf® from Eppendorf-Netheler-Hinz GmbH).
Furthermore, instructions are known to measure individual samples also without preceding analyses. which, however, are very immovable owing to a high integrated measuring comfort, thus being unsuited for a local application (YSI 2300 STAT of YSI Incorporated and STAT Profile PLUS of NOVA BIOMEDICAL GmbH).
For the time being, commercially available mobile systems with integrated biosensors are too expensive owing to the high measuring comfort (internal calibration). They require too much maintenance and are operated with excessively long transport ways for the sample to be measured. For this reason, in addition to a comparatively high price, delays and pollution will result which have detrimental effects on the quality of analysing.
All measuring systems applied locally to determine parameters such as glucose and lactate are at present based on non-reusable consumables (test strips, photometric; strip electrode, amperometric). Thus the analysis is determined by the price of the test strip and the test strip can not be calibrated as it may only be used once.
The ‘mobile hand-held device with biosensor’ of GM 29511566.1 represents a significant improvement. That instrument is based on a reusable biosensor allowing the calibration of the sensor resulting in an improved quality of analysis as compared to the disposable test strips. Further advantages result from lower costs of the analysis.
As compared to the high quality results of laboratory analysis the mobile hand-held device of GM 29511566.1 is characterized by mobility and constant quality, i.e., decentralized analysis of high quality is possible independent of the laboratory using this instrument.
However, the technical realization of the measuring procedure has become disadvantageous during practical use. The operation of two different operation elements in parallel is complicated and may cause handling errors.
That is why it was the task of the invention to provide a technical solution for providing a locally applicable equipment for the examination of blood, urine, liquor without preceding analyses being carried out and a re-usable biosensor which is marked by a high quality of analysis, a low price and a simple operation procedure.
The task will be solved by the construction of a hand-held apparatus with linear operation.